def act(self, token):
word = token.word
if word == ':':
if self.compile:
print('Already in compile mode!')
return False
self.compile = Compile()
elif word == ';':
if not self.compile:
print('Not in compile mode!')
return False
self.compile.finish(self)
self.compile = None
elif self.compile:
try:
self.compile.take(token)
except CompileException as e:
print(e)
self.compile = None
elif word == 'variable':
if self.lex:
name = next(self.lex)
if name.isstringliteral:
raise ForthException('Expected name, not string')
name = name.word
index = self.memory.create_var(name)
self.on(name, lambda s: s.istack.push(index))
else:
raise ForthException("No name variable name given")
elif word == 'constant':
if self.lex:
name = next(self.lex)
if name.isstringliteral:
raise ForthException('Expected name, not string')
name = name.word
n1 = self.istack.pop()
self.on(name, lambda s: s.istack.push(n1))
else:
raise ForthException("No name variable name given")
elif isInt(word):
self.istack.push(int(word))
elif isFloat(word):
self.fstack.push(float(word))
elif token.isstringliteral:
print(word, end='')
elif word in self.dict:
self.dict[word](self)
else:
raise ForthException('Unknown Token: ' + word)
return True
def __parse_string(self):
''' Helper method to consume and return input until a trailing " is found '''
# Skip the ." and space
self.index += 3
text = self.__take_until(lambda c: c == '"')
if not self.__curr() == '"':
raise ForthException('Incomplete string')
self.index += 1
return Token(text, True)
def __parse_comment(self):
''' Helper method to consume input until a trailing ) is found '''
self.__take_until(lambda c: c == ')')
if not self.__curr() == ')':
raise ForthException('Incomplete comment')
self.index += 1
def pop(self):
if self.is_empty():
raise ForthException('Stack underflow')
self.length -= 1
return self.stack.pop()
def peek(self, level=1):
if level > self.length:
raise ForthException('Stack underflow')
return self.stack[-level]
def set_val(self, addr, val):
if addr < 0 or addr >= self.used:
raise ForthException('Address out of bounds ' + repr(addr))
self.memory[addr] = val
def get_val(self, addr):
if addr < 0 or addr >= self.used:
raise ForthException('Address out of bounds ' + repr(addr))
return self.memory[addr]
def get_var(self, name):
if not name in self.vars:
raise ForthException('No variable named ' + name)
return self.vars[name]
def create_var(self, name):
if name in self.vars:
raise ForthException('Variable already exists ' + name)
index = self.allot()
self.vars[name] = index
return index